JPH01243351A - Analyzer - Google Patents

Abstract

PURPOSE:To calculate the depth of the analysis position of a sample and improve the precision of the analysis result by detecting the position in the sample front direction of a secondary energy beam generated by the radiation of a primary energy beam and measuring the time to detect the secondary energy beam. CONSTITUTION:A primary energy beam 3 is radiated to a sample 1, particles constituting the sample 1 are emitted and ionized into secondary ions as a result of spattering on the surface. The secondary ions are accelerated vertically to the sample 1 toward a detecting means 5 by the electric field generated by an extracting electrode 4 to become a secondary ion beam 9. This beam 9 passes the magnetic field 7 before passing the means 5, only the element desired to be analyzed is fed to the means 5 by the magnetic field 7, other elements are separated to separate directions according to masses. The detection result by this means 5 is inputted to a control means 8, the concentration of the sample 1 at the point A is calculated based on the incidence quantity of the element X, the positions of the sample 1 in the surface direction from the arrival point C to the point A are calculated, and the depth of the analysis position is determined.

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an analysis device that utilizes secondary ion mass analysis, Auger electron spectroscopy, etc., and more specifically, it is used to calculate the depth of a position to be analyzed. Regarding analysis equipment.

(b) Taking the conventional technology secondary ion mass spectrometer as an example, this
is generally an ion system in which the generation, acceleration, adjustment, etc. of primary ions such as Seshikumuiman are performed.

and a secondary ion system in which mass separation, detection, etc. of secondary ions generated from the sample are performed.The sample n1 is placed at the contact point between the Ikku ion system and the secondary ion system.

When a sample is irradiated with primary ions, the particles that make up the sample are ejected as a result of sputtering that occurs on the sample surface, but some of them are ionized.

It becomes a secondary ion. By mass-separating the secondary ions and measuring the intensity ft of the secondary ions having a specific quality, the concentration of a desired element can be determined.

This secondary ion quality can be determined by using an analytical method that involves sputtering with ions, which destroys the sample surface. Directional concentration distribution analysis can be performed. In other words, since a crater is formed in the t part of the sample surface by irradiation with ions, the depth of this crater (total sputtering depth) is measured with a stylus step meter after the sputtering (analysis) is completed. By making the measurement result of the temporal change of the next ion correspond to the total sputtering time in a proportional relationship, a degree distribution in the depth direction can be obtained.

In such analysis in the depth direction, the IW prerequisite is that the sputtering rate is constant, that is, the sputtering time and the sputtering depth are in a proportional relationship. However, the sputtering rate during sputtering (analysis) is not necessarily constant, and especially in multilayer films where multiple types of thin films are laminated, the sputtering rate may vary greatly between each layer. However, there is rRn, which causes a large error in the analysis results in the depth direction. Also, it is not possible to know the current sputtering depth at any time during the analysis. Furthermore, the sample must be taken out of the apparatus and investigated using a stylus. Since this method requires the work of measuring the depth of a crater, there are problems with the speed and accuracy of one analysis.

(, J Problems to be Solved by the Invention The present invention is capable of knowing the correct sputtering depth, that is, the depth of the analyzed position, at any time during sputtering or analysis.
It is an object of the present invention to provide an analysis device that does not cause errors in analysis results in the depth direction even when analyzing multilayer films.

B) Friendly means for solving the problem The analysis apparatus of the present invention includes means for detecting the generation position of the secondary energy beam in the direction of the sample surface generated by irradiation with the primary energy beam, or a means for detecting the generation position of the secondary energy beam in the direction of the sample surface. The present invention is characterized in that it includes means for measuring the time until detection, and means for calculating the depth of the position to be analyzed in the sample from the position of occurrence or the time until detection.

(e) By means of detecting the generation group of the acting secondary energy beam in the direction of the sample surface, or by means of measuring the entire time until detection of the secondary energy beam, the secondary energy beam becomes M4. An l# signal in the opposite direction was detected, and -! 1. The closure of the analysis tzi is calculated.

(to) fossa * even Embodiment 1c) of the present invention will be described in detail with reference to FIG.

(1) has a surface shown in the analysis execution rule as ``broken''.

For a certain element
t - Incidence of 14 degrees θ (0" to θ (90") for sample (1)
), the ion generating means (4) is disposed facing the sample (1) and is irradiated with an electric current of 4.5 KV to the sample (1+).
(13) is applied to the fL-order extraction electrode, (5J is the secondary energy beam that is applied to the sample (1), and (6) is the detection means that detects the generation position in the surface direction of the secondary energy beam. A magnetic field generating means (81) controls the magnetic field generating means (2) and the magnetic field generating means (6) to generate a magnetic field (force) during the passage route, and analyzes the detection results from the detecting means (5). control means.

When the sample is irradiated with the primary ion beam (3) and analysis is started, as a result of sputtering that occurs on the surface of the sample (1), particles constituting the sample ill are emitted and ionized. It becomes the next ion. These secondary ions are detected by the detection means (
5) A secondary ion beam (9) corresponding to a secondary energy beam is accelerated vertically from the sample [1) toward n. The secondary ion beam (9) passes through a magnetic field (7) before reaching the detection means (5). The secondary ion beam (9) contains various elements that collect the sample (1), and this magnetic field (force) is formed so that only the desired element X to be analyzed enters the detection means (5). The elements in the pond are separated according to their masses in the direction perpendicular to the plane of the paper in Figure 1.The secondary ion beam (9a) generated from point A on the surface (a) of the sample (1) at the beginning of analysis , the element X therein is detected by the detection means (
5), the 0 point is reached, and its S degree (throughput of incidence) and the reached position are detected. d” both means [83 is the detection means (5)
A degree at point A of sample Ill is calculated from the amount of element

As the analysis continues, the surface of the sample (1) is destroyed as a result of sputtering caused by irradiation with the primary ion beam (3), creating a step there. The analysis has progressed a little since the beginning,
The surface of the sample 111 is sputtered to the position 4 in FIG. 1 (FIG. 1 is exaggerated). At this time, the ion beam (3) is irradiated to point B of the sample, and the secondary ion beam (9b) generated from point A and B is detected by the detection means (5).
reaches point D and is detected. The control means (8) controls the element
Calculate a degree at point B of sample 11) from the incident amount of From the calculated surface direction position of point A and the irradiation angle θ, the sample il+
The chestnutness (d) from the analyzed position (Table On) of the analyzed position (point B) is calculated. That is, here, d=cD/lanθ -----・(1) is added to the depth (d
J can be calculated. However, CD is the distance between point 0 and point D.

By continuing the sputtering analysis as described above, it is possible to analyze the concentration distribution of element Because it fades at any time, the correspondence between 9 degrees and position is accurate, and the IIk degree distribution in the n-th depth direction obtained as an analysis result is also accurate. There is no need to measure the total sputtering depth, and errors due to differences in sputtering speed between layers do not occur when analyzing samples such as multilayer films.

However, the depth of the analysis target position can also be calculated by measuring the time until the detection of the secondary energy beam, which will be described below as a second embodiment.

Now, in the same Shinsei as shown in Fig. 1, a part of the ion beam (3), which is the primary energy beam, collides with the surface of the sample (1) and is reflected on the path of the secondary ion beam (9) in the first embodiment. This is regarded as a secondary energy beam. That is, it collides with the sample (11) and loses its 4th energy, 7?
The ions of the secondary ion beam (3) are extracted! :f
It is accelerated by the near field created by i (4) and becomes a secondary ion beam (9).

In this case, the ions reflected at the point A at the depth shown in [1st (2)] (the ions reflected at the point B of the mountain are exposed to one surface), and the path is longer by AB in one reflection than the t ion, and by d after the reflection. (AB
=d/cosθ]. Therefore, in the case of reflection at point B, the time from the initial construction of the ion beam (31) in the ion generation means (2) to the detection of the secondary ion beam (9) in the detection means (5) is Compared to the case of reflection at point A, it becomes longer by Δt, which is determined by dJ.
and q have 4 lines of ions and charges, vl & 1000 ions are generated between the hand group (2) and sample 11), and a single pole is drawn out to V2 (
4)-Sample (13 between 1 and 1 is the distance between la and
The depth d is very small compared to the distance between the ion generating means (2) and the sample (1), and the charge does not change even if d changes. ) is assumed to lose all its kinetic energy in collision with a surface.

Therefore, if the time until the detection of the ion beam is measured by the suppressing means (8) at any time during sputtering, and the time difference Δt between the time when the ion beam is reflected from the surface of the sputtering surface 4H and the time difference Δt is determined, then the above ( 2) The depth of the measured position can be accurately calculated using the formula. Operation 4 for determining the depth d from the water tank Δt using the above equation (2) can be performed by a microcomputer or the like in the control means (8).

Furthermore, if the present invention is applied, the sputtering depth can be measured even when the entire surface of the sample tl) is sputtered as shown in FIG. In the conventional analytical method of measuring the sputtering depth using a stylus-type step meter, etc., only a part of the sample is sputtered and forms a crater, as shown in Figure 3.The other part is the part before sputtering. If the sample remained, it could be measured, but if the entire surface of the sample was sputtered, as shown in FIG. 2, it was impossible to measure the depth.

In the above implementation, the energy beam is primary,
Although the ion beam was used in all phases for the secondary, it is also possible to use neutral particles or electrons, for example, and it is also possible to use different energy beams for sputtering and analysis, such as using ions for sputtering and electrons for analysis. . Furthermore, the present invention is applicable to secondary ion mass spectrometry, Auger electron spectroscopy,
It can be used in various analytical methods such as photoelectron separation method. .

(G) Effects of the Invention By incorporating the present invention, it is possible to accurately calculate the depth of the position to be analyzed at any time during sputtering or analysis, and accurate analysis can be performed even when analyzing multiple films. 3° where you can get bad luck

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the analyzer of the present invention, and FIGS. 2 and 3 are #T side views showing the state of the sample. (11... sample, (2)... ion generating means, (3
)...-ku ion beam, (5j... detection means, (
8)...system's means, (9)...secondary ability system.

Claims (2)

[Claims] (1) A means for irradiating a sample with a primary energy beam at a predetermined angle, and detecting the generation position in the direction of the sample surface of a secondary energy beam such as sample particles emitted from the sample by irradiation and excitation of the primary energy beam. and means for calculating the depth of the sample position to be analyzed from the detected occurrence position and the angle. (2) A means for irradiating a sample with a primary energy beam, a means for detecting a secondary energy beam such as sample particles emitted from the sample by irradiation and excitation of the primary energy beam, and a time required for such detection. An analysis device characterized by comprising: a measuring means; and a means for calculating the depth of a position of a sample to be analyzed from the measured time.